Yes, if you read the old magazines from that era, the addition of the fan was a selling point for their memory upgrade. Larry Pina (Mac Upgrade & Repair Secrets) also recommends installation of a fan as a matter of course when doing a power supply (analog board) upgrade on any 128, 512 or Plus mac. Do you still have some kind of Max memory upgrade in the computer, or is the fan the only artifact?
Neat to actually see one! I didn't know they were so... colorful. The piezoelectric type fans are rarer than the squirrel cage type as a rule.